In order to determine, for example, the rotation position of a rotatable component, in many cases a material measure (measuring element/measuring reference), which is located opposite a sensor surface of a sensor unit and which is scanned by a sensor surface, is mounted on the rotatable component. Newer systems, which are known, for example, from DE 10 2010 061 738.5, use in this case a material measure, which does not extend over the entire 360° of a rotation and forms a gap between its ends. In order to bridge over this gap, it is necessary to use two or more sensor surfaces, whose distance from one another is greater than the gap, for determining the position. A gap within the material measure is also frequently found in linear measuring systems, since the material measures often cannot be produced or transported for a correspondingly long time. In other measuring systems as well, for example, in those which operate with nonius or additional pseudo-random-code traces, it may be necessary that at least two sensor surfaces, which are arranged offset in a circumferential direction of the rotatable component or in the direction of travel of a linearly movable component, be present.